This proposal is a request for funds to purchase a new radio-frequency console, probes and accessories for an existing older 500 MHz NMR spectrometer. The upgraded system, which is actually on loan at the University of Michigan now, provides state-of-the-art multi-dimensional multi-nuclear magnetic resonance support for NIH supported faculty in the Biophysics Research Division and the Department of Biological Chemistry at the University of Michigan. The faculty involved is generally researching biological systems of molecular size exceeding 15 kDa. Because of this size, NMR support for their research will almost exclusively rely on advanced and time-consuming experiments in two, three and four dimensions involving up to four nuclei simultaneously with isotopically enriched materials, necessitating the upgrade. The purchase of the upgraded instrument will immediately benefit PI and six other major users who hold a total of 9 active PHS-sponsored research grants, one institutional training grant and one pending grant. Specific projects are: 1. NMR structure determination of stromelysin catalytic domain 2. Methodology development in Multi-nuclear Multi-dimensional NMR 3. NMR studies of Phosphatases in Solution 4. Determination of a high-resolution solution structure of T4-lysozyme by Multi-dimensional NMR 5. NMR studies of the structures of catalytic RNA subdomains 6. Studies of the interaction of alpha2 adrenergic receptor peptides with G-protein subtypes 7. Electron Transfer and conformational gating in Flavodoxins: NMR analysis of E. Coli Flavodoxin